Interior CMU Wall 4

[BONILL]

I have an interior 8" thick cmu wall used only for division purposes (non load bearing). The wall spans 5.80m. (between the top of concrete slab below to bottom of concrete slab above). It is connected to the concrete slab below with dowels.

For pressure out of plane I considered the following:

1. W = 10 psf minimum wind load for interior walls.
2. W = 0.40 x SDS x I x Wc for seismic.

My design tells me that I should connect the cmu wall at the top to the slab above using dowels, and with this simply supported condition, I should use #3 @ 16" o.c. as flexural steel. I am also using a 8" x 12" beam at mid height of the wall and a 8" x 12" beam at the top of the wall. I'm also prescribing 8" x 8"columns at 5m. o.c.

Am I missing anything?

 

[mijowe]

not sure why you need the mid height beam or columns. The top bond beam is good for distributing the top to bracing points.

for non load bearing walls, it is good practice to provide room for the floor above to move without loading the wall, ie a slip joint. depending of the type of structure this may be more or less critical.

 

[MiketheEngineer]

Usually only need 5 psf wind for internal walls??

 

[concretemasonry]

No mid height reinforcement is needed. The 12" height in an 8" thick wall does not seem proper or economical. horizontal joint reinforcement would be nice.

A bond beam (usually 8" high)at the top of the wall seems sufficient, more practical and preserves the modularity of the height unless there is a special height requirement.

Dick

Engineer and international traveler interested in construction techniques, problems and proper design.

 

[JAE]

I would second mijowe's suggestion for a slip joint.

 

[wannabeSE]

ASCE 7 Chapter 13 should be used for seismic loads on masonry partitions. W = 0.40 x SDS x I x Wc is for structural walls.

 

[UcfSE]

I would keep the beams at a block dimension. A midheight beam is fine if you need the extra horizontal reinforcement. 10 psf wind seems a little high for a typical interior wall. The minimum lateral live load is 5 psf. Do you need more? #3 at 16" seems odd. I would pick at least a #4 or #5 and space the vertical bars farther apart.

 

[msquared48]

I agree with UcfSE and Mijowe.

Mike McCann
MMC Engineering

http://mmcengineering.tripod.com

 

[DST148]

@ BONILL - Ref ASCE 7-05: o.4 x Sds x I x W is applicable for structural walls only.
For interior nonstructural partitions 13.3 is applicable. The force will depend on the location of the partition(z) in relation to the overall height of the structure(h). In a high-rise building, the force on the partition on the upper floors will be much higher than the partition on the ground floor.